The present application claims priority under 35 U.S.C. xc2xa7119 of Austrian Application No. 1155/2000 filed on Jul. 5, 2000.
1. Field of the Invention
The invention relates to a process for producing supply stock for saw blades or saw belts with a carrier part and a blade part made from different materials becoming metallically bonded to one another by welding, and with the thickness of the bonded or bi-metal part being adjusted or set and the supply stock being formed.
Additionally, the invention includes supply stock for the production of saw blades or saw belts comprising a carrier part and at least one cutting part, which parts are metallically bonded to one another by welding, forming a bi-metal or tri-metal bonded part, and with the supply stock being adjusted in its thickness.
2. Discussion of Background Information
Due to different wear during use, on the one hand, saw blades or saw belts must be able to compensate high bending, tensile, and transverse strain in the blade part or carrier part and, on the other hand, must be provided with high stability of shape of the cutting edges and/or high abrasion resistance and/or wear resistance of the edge tips.
It is known to produce saw blades or saw belts from a supply stock comprising different material parts, i.e., a carrier part and/or carrier belt made from a tenacious material and a blade part made from a material that can achieve high hardness and high wear resistance by means of thermal hardening. For producing such a so-called bi-metal or tri-metal belt, a carrier belt and at least one cutting material belt are bonded to one another without any additional material, in most cases using laser welding or electron-beam welding.
However, the weld joint of the material parts can represent a problematic zone with respect to production technology and metallurgy. On the one hand, a complete welding of the narrow sides of the belts is to be achieved; on the other hand, undesired bulging of the weld seam and/or the formation of a disturbing, raised welding bead is to be avoided. Additionally, the welding bead and/or the bond region formed during welding are provided with lower tenacity and high stability of the material regarding changes in shape.
In order to avoid weld joint bulges to a large extent, welding technologies have been optimized for that purpose; however, during the complete welding of the narrow sides of the belts, the formation of a convexly protruding welding bead can occur at least on one side.
It is common in the prior art, subsequent to the welding of the carrier part to the blade part, to mill and/or adjust the bonded belt with respect to thickness, which is called dressing by one skilled in the art, thus producing a supply stock for the production of saws not containing any convex or protruding regions on the lateral surfaces. These lateral surfaces are called belt surfaces. However, this measure, though counteracting increased friction between the saw blade and the material to be sawed, has the disadvantage that, on the belt surfaces, the protruding regions of the welding beads are pressed into the supply stock/belt cross section with an increased deformation. Thus, tapering of the material on both sides of the milled volume areas in the belt can occur and longitudinal grooves can be present on both sides of the deformed welding bead in the belt.
However, these longitudinal groves in the bond region of the two material parts have the disadvantage that, subsequent to the forming of the tooth spaces, the grooves in the tooth region can cause increased tension in the base of the notch, thus presenting the danger of tears arising that may cause the fracture of tooth tips during practical operation of the saw or a shortening of the life of the saw.
With respect to improving the quality of the supply stock and, ultimately, achieving a high saw quality, an object of the invention is to avoid longitudinal grooves in the bond region of the two material parts of the and/or at the supply stock and to restrain the danger of tears arising from grooves in the longitudinal direction of the belt in the bond region of the material parts.
The invention therefore provides for a process of the type mentioned at the outset in that, subsequently to welding the parts, at least one side of the surface of the bonded part is worked in a cutting fashion at least locally in the region of the connection and the bulging of the welding seam and/or welding bead is removed.
The advantages achieved with the invention can essentially be seen in the fact that, in spite of an adjustment of the plane parallelism of the belt, the build-up of mechanical stresses in the same can be minimized, in particular, can be prevented. Therefore, no increased local material tensions caused by the milling of bulging in the welding region are present between the carrier material and the cutting part, which provides improved use characteristics with an extended life span for a saw made from the supply stock.
Particular advantages regarding the quality of the bond of the parts and regarding the quality of the saw ultimately made from the supply stock is achieved when the weld joint bulging is removed by grinding, in particular polishing.
However, it may be important and advantageous here for the cutting or the polishing of the bonded part to occur in a direction for removal of the material which is perpendicular or diagonal to the longitudinal direction of the bonded part, and for the tool and the bonded part to be moved relative to one another in the longitudinal direction.
The quality of the belt surfaces of the supply stock for a saw made from this material can be improved and the friction between the saw blade and the material to be sawed can be reduced in an advantageous manner when subsequent to the cutting of the bonded part, a post milling occurs for the purpose of adjusting or setting the thickness of the supply stock for saws.
The further object of the invention is achieved by the appropriate supply stock for the production of saw blades or saw belts in that, at least in the bonded region of the carrier part and the cutting part, the surfaces of the supply stock belt are formed without longitudinal ridges. The advantages thus achieved must be considered essentially in that no temperature peaks in the material can occur near the surface during thermal hardening of the saw blade, caused by ridges. Additionally, no tearing initiation points are present so that during the use of the saw the danger of tooth tips fracturing is low.
The initiation of tears originating from grooves and the breaking off of the tips of cutting parts caused thereby can be avoided to a large extent when at least one side of the surface of the supply stock is provided with a grinding structure or grinding grooves, at least in the bonded region of the parts, which are perpendicular or diagonal to the longitudinal direction of the supply stock.
Particularly high requirements for the quality of the supply stock can be achieved when additionally, as can be advantageously provided, the supply stock is finally provided with a surface adjustment and/or thickness setting by means of post milling.
The invention provides for a process for producing supply stock for a saw member that comprises at least a carrier part made of one material and at least a blade part made from a different material. The process comprises welding the carrier part to the blade part to form the supply stock having a thickness defined by a first and a second surface, forming a welding bead in an area where the carrier part is welded to the blade part, the welding bead having a projecting portion which projects beyond at least one of the first and the second surface, and removing material from at least a portion of at least one of the first and the second surface.
The removing may reduce the thickness of at least a portion of the supply stock and removes material from the projecting portion. The saw member may comprise one of a saw blade and a saw belt. The forming may comprise producing the welding bead so that a portion projects beyond each of the first and the second surface. The removing may comprise removing material from at least a portion of each of the first and the second surface. The removing may comprise removing material from at least a portion of each of the first and the second surface. The removing may comprise removing material from each of the first and the second surface of the supply stock. The removing may comprise grinding. The removing may comprise grinding and polishing. The removing may comprise removing material in a direction which is not parallel to a direction of the welding bead. The removing may comprise removing material in a direction which is at least one of diagonal and perpendicular to the direction of the welding bead.
The invention also provides for a supply stock for a saw member comprising at least a carrier part made of one material and at least a blade part made from a different material. The carrier part is connected to the blade part by welding to form the supply stock. The supply stock has a thickness defined by a first and a second surface. A welding bead is located in an area where the carrier part is welded to the blade part. The welding bead has a projecting portion which projects beyond at least one of the first and the second surface. At least one of the first surface, the second surface, and the projecting portion comprises a surface which has been subjected to material removal by cutting.
The thickness of the supply stock may be less than a thickness of at least one of the carrier part and the blade part. The saw member may comprise one of a saw blade and a saw belt. The welding bead may comprise projecting portions which project beyond each of the first and the second surface. Each of the first surface, the second surface, and the projecting portions may comprise a surface which has been subjected to material removal by cutting. Each of the first surface and the second surface may comprise a grooveless flat surface which has been subjected to material removal by cutting.
The invention further provides for a process for producing supply stock for a saw member that comprises at least a carrier part made of one material and at least a blade part made from a different material. The process comprises welding the carrier part to the blade part to form the supply stock having a thickness defined by a first and a second surface, forming a welding bead in an area where the carrier part is welded to the blade part, the welding bead having a first projecting portion which projects beyond the first surface and a second projecting portion which projects beyond the second surface, and removing material from at least one of the first projecting portion and the first surface, and the second projecting portion and the second surface. The removing reduces the thickness of the supply stock.
The saw member may comprise one of a saw blade and a saw belt. The removing may comprise removing material from each of the first and the second surface. The removing may comprise one of grinding and grinding and polishing. The removing may comprises removing material in a direction which is not parallel to a direction of the welding bead. The removing may comprise removing material in a direction which is at least one of diagonal and perpendicular to the direction of the welding bead.
The invention additionally provides for a supply stock for a saw member that comprises at least a carrier part made of one material and at least a blade part made from a different material wherein the supply stock made by a process comprising welding the carrier part to the blade part to form the supply stock having a thickness defined by a first and a second surface, forming a welding bead in an area where the carrier part is welded to the blade part, the welding bead having a first projecting portion which projects beyond the first surface and a second projecting portion which projects beyond the second surface, and removing material from at least one of the first projecting portion and the first surface, and the second projecting portion and the second surface. The removing reduces the thickness of the supply stock.